Synthesis and characterization of poly(ethylene glycol)-poly(D,L-lactide-co-glycolide) poly(ethylene glycol) tri-block co-polymers modified with collagen: a model surface suitable for cell interaction.

This study focused on the synthesis and characterization of poly(ethylene glycol)-poly(D,L-lactide-co-glycolide)-poly(ethylene glycol) tri-block co-polymer (PEG-PDLLG-PEG), and its modification with type-I collagen. To this aim, a PEG-PDLLG-PEG tri-block co-polymer was synthesized in two steps by reacting poly(ethylene glycol)bis(carboxymethyl)ether with thionyl chloride to obtain an acyl-halide-terminated poly(ethylene glycol) and subsequently coupling this compound to hydroxyl-terminated poly(D,L-lactide-co-glycolide) (PDLLG). The new carboxyl endgroups of PEG-PDLLG-PEG were subsequently reacted with N-hydroxysuccinimide (NHS) in the presence of the hetero-bifunctional cross-linking agent dicyclohexylcarbodiimide (DCC) in order to activate the co-polymer for coupling with collagen.

The effects of lyophilization on the stability of liposomes containing 5-FU.

Multilamellar liposomes containing 5-fluorouracil (5-FU) were prepared by modified lipid film hydration method and were lyophilized with or without saccharose as cryoprotectant. The effect of lyophilization on the stability of liposomes was evaluated by comparing the vesicle size, encapsulation efficiency and the drug release rate before and after lyophilization/rehydration. The process of lyophilization, without cryoprotectant, resulted in particle size increase and significant content leakage.

Gastrointestinal malignant lymphomas in Macedonia.

The gastrointestinal tract including oral cavity is the most common location of extranodal lymphomas. In this retrospective study, the histomorphological, immunohistochemical and clinical features of 21 Macedonian cases with diagnosed malignant lymphomas were investigated. The series included 15 males and 6 females, mean age 44 (4-78) years.